I recently participated in a dinosaur egg & nest excavation conducted by the Two Medicine Dinosaur Center (TMDC) based in Bynum, Montana.
Bynum is a small agriculturally based community located in Teton County in northwestern Montana east of the Rocky Mountain Front. Bynum is about 13 miles north of Choteau, the Teton County seat. Situated on the western edge of the Great Plains where the Rocky Mountains literally jump up out of the plains and reach for the sky, this area represents a very stark, dramatic, and ever-changing landscape. This is epitome of Big-Sky Country for sure. Being there you are always aware of the fact that you are at the mercy of the weather. You cannot escape it!
In the not to distant past, this area was the realm of the American Bison or Buffalo and home to the Blackfoot Indians who relied on the Buffalo for food and all their basic needs. Eons ago, during what scientists have named the Cretaceous Period, this area was a tropical upland adjacent to an inland sea located further to the east that supported a large variety of dinosaurs. The Bison and the dinosaurs are long gone, but their bones remain waiting to be discovered.
THE TWO MEDICINE DINOSAUR CENTER:
View of the Two Medicine Dinosaur Center, Bynum, Montana.
This rural Montana museum has some interesting dinosaur exhibits. However, it is unique in that it provides a large variety of half-day, full-day and multi-day scientific dinosaur dig programs for the general public. Participants range in age from children to senior citizens without discrimination as to background or experience. Available dig programs vary from a relatively short 3-hour site visit to a more extensive 10-day volunteer training program. I should mention that it is very difficult if not almost impossible for the general public to gain access to sites containing significant dinosaur remains and then to participate in excavation programs under proper supervision. The TMDC nicely opens the door of opportunity to that unique experience. Fees to participate in their programs are very reasonable and are really only designed to cover costs. For more detailed information on the TMDC and their public programs, please visit their website.
Programs at the TMDC are supervised by David Trexler, Paleontologist, along with the assistance of several able and knowledgeable staff members. Dave is not your customary egotistical academic egghead scientist who likes to do his research out of the public view, perhaps teach a select few graduate students, and then to publish his results in scientific journals to gain fame and recognition amongst his scientific peers. That is Academia in general, but that is not Dave Trexler. Rather, I found Dave to be a very friendly, humble, yet very knowledgeable individual who is openly willing to share his special knowledge and practical expertise in paleontology with a broad spectrum of the public that participates in his field programs. I was pleased to see how he treats all of his participants equally, always willing to answer even the very basic of questions. He is especially great with kids - never bored with their floods of questions about various dinosaur species. In fact, he will often ask kids, "what is your favorite dinosaur?" And then, he really listens to what they have to say in response to that question. He never talks down to anyone, but always tries to meet people at their level and to engage them in meaningful conversation. You don't find folks like Dave Trexler too often in the scientific world.
THE BACK STORY:
My interest in dinosaurs goes way back to my teen age years living in New Jersey. Periodic visits to the American Museum of Natural History in New York City would stimulate that interest. I would always bypass all the other exhibits in the museum and head for the dinosaur exhibits on the 4th floor for my dinosaur fix. But, my ultimate career choice to be a microbiologist / environmental scientist would take me away from dinosaurs, but not permanently away from a latent interest in them, in geology and in the past history of the earth in general.
Living in Montana provides me with some unique opportunities to satisfy my curiosity about the past history of the earth and what life was like here in the very distant past. My most recent interest in paleo history and dinosaurs was stimulated in part by this Geologic Road Sign (see below) found on Montana Highway 287 between Choteau and Augusta. I invite you to read the text in detail and you will understand more why I decided to see if there was any way that I could participate in a dinosaur dig that would help to satisfy my curiosity regarding the paleo history of Montana.
Turns out that Marion Brandvold was Dave Trexler's mom. In his youth growing up on a ranch in Bynam, Montana, Dave and his mom used to hop onto his Kawasaki motorcycle and go on fossil and mineral hunting trips in the Choteau and Bynum area. With the permission of local ranchers they covered a wide area visiting badland outcrops all over the area looking for dinosaur bones and minerals. One day his mom discovered a set of baby dinosaur bones (as noted on the sign) and, as they say, the rest is history.
Marion Brandvold's unique find ultimately got the attention of Jack Horner from the Museum of the Rockies in Bozeman, MT. Horner visited the site of the find with Mrs. Brandvold with Dave Trexler present as well. Mrs. Brandvold told Horner that she thought the adult dinosaurs took care of their young. Horner was not immediately convinced of this as the conventional assumption at the time was that dinosaurs behaved like overgrown modern reptiles, who did not stick around to care for their young. Later, after several expeditions to the site began to uncover dinosaur nests, eggs, and more skeletons of hatchlings and baby, as well as, adult dinosaurs, the conventional assumptions began to change. These proved to be the first dinosaur nests found in the western hemisphere and the first dinosaur embryos ever discovered in the world. Further research revealed that these dinosaurs were likely "warm blooded" like modern birds. They lived in large herds like the more modern Buffalo, nested colonially, and cared for their young in the nest. Many publications followed and the scientific world was amazed at what was found at "Egg Mountain" in Montana. As it turned out Mrs. Brandvold proved to be correct, as the scientific evidence accumulated that some species of dinosaurs apparently cared for their young. The original "Egg Mountain" site is now owned by the Museum of the Rockies and is essentially "off-limits" to others.
The Two Medicine Geologic Formation is found in numerous other outcrops throughout the area. It is in that formation that evidence of dinosaur nesting activity can be found. Dave Trexler has obtained permission from local ranchers to visit these areas and to conduct investigations and excavations to add to the body of information on dinosaur nest construction and nesting activity. Most of the current research by others has concentrated on the eggs in the nest and on the skeletal remains of the young dinosaurs, but not on the entire nest structure. Dave Trexler hopes to find and excavate a complete dinosaur nest and this is the focus of one of his current public field investigation programs - a program that I had an opportunity in which to participate.
SOME BACKGROUND INFORMATION ON DINOSAURS THAT CARED FOR THEIR YOUNG:
Maiasaura peeblesorum is a species of Duckbill dinosaur that inhabited the Choteau area during the Cretaceous period. After emerging from their eggs, Maiasaura babies were helpless and vulverable. About a foot in length, newborn Maiasaura babies could not walk and had to stay in their nests until their legs were strong enough to support them. While in the nest, the Maiasaura hatchlings were cared for by their parents.
PREVIOUS AND CURRENT FIELD INVESTIGATIONS:
Based on his previous research and field investigations, Dave Trexler believes that the adult Maiasaura constructed their nests of individual mud balls arranged in a circle or oval. The nests would serve to contain the eggs and to "corral" the young hatchlings until they were able to move around on their own.
In 2012, Trexler found what appeared to be a prospective nest site located on the top of a mound that was associated with an outcrop of the Two Medicine Formation located several miles west of Bynam on a private ranch. He named the site "The Eyrie" and gave it the site inventory designation "TA2012.2." The site name means "a large nest of a bird of prey, especially an eagle, typically built high in a tree or on a cliff." Turns out that the selected site name fits the site conditions almost precisely, but not for an eagle nest, but for a dinosaur nest. Preliminary investigations at the site in 2012 showed the slope leading up to the mound littered with bits of dinosaur egg shell with a circular area at the top that resembles the faint outline of a what may well be a nest. Some concentrations of egg shell were found and were stabilized with plaster of Paris covers. Then most of the area was covered with a cloth mesh to protect it until such time that the site could be revisited for further study and excavations.
Fast forward to July 2015. On July 15, 2015, David Trexler along with several volunteers including myself, visited the site. The first step was to remove the protective cloth over the area, much of which had deteriorated due to exposure to the weather and UV light and to clear the prospective excavation area of some mineral detritus that littered the site. Then over the next several days the task was to slowly and deliberately remove layers from the prospective nest area to try to ascertain the configuration of the nest structure. The soil layers on top of the nest were slowly excavated using dental picks and brushes so as not to miss any items within the nest area. Items found included some minor amounts of egg shell and a variety of microfossils (mainly gastropods). Structurally, what appeared to be a loaf of bread shaped solidified mudball was uncovered along with evidence of several soil faults in the nest area. So far, no eggs or bones were uncovered. The location's GPS coordinates and the elevations associated with selected features within the nest area were determined using a Topcon Total Station and tied to known benchmarks. In addition, a site sketch was prepared, notes prepared each day and site photographs were taken to fully document the results of the site investigations.
The interior and exterior of a typical egg shell fragment collected from the excavation site was imaged using macro imaging techniques with a Canon 5D Mark II DSLR equipped with a B&L Micro Tessar lens set at f/8 and under ambient light conditions. The typical shell fragment exterior has a rough bumpy outer surface. On the other hand, the interior surface of the fragment is relatively smooth and shows a definite concave radius or curvature.
Additional excavations at this site scheduled for mid-August will hopefully begin to reveal more details of the nest structure and hopefully some eggs and possibly juvenile dinosaur bones or embryos. Stay tuned for updates.
2016/2017/2018 UPDATE:
Additional continuing excavations at the Eyrie site west of Bynam, MT during the summers of 2016 to 2018 finally yielded several dinosaur eggs. However, all were found in a crushed state with no embryonic remains inside. To date a total of 14 plaster-jacketed eggs (includes 3 partial eggs) have been recovered from the site, with 9 of the eggs believed to be from a discrete clutch. Laboratory investigations on the nature of the eggshell material is ongoing.
Details on the results of the ongoing investigations are found in the following papers that can be accessed via the Research Gate website:
Przybyszewski, Eric & D Germano, Paul & Varricchio, David & Trexler, David. (August 2017). Filling a Data Gap with Analysis of Fossil Eggshell from the Late Cretaceous Upper Two Medicine Formation of Montana.
Przybyszewski, Eric & D Germano, Paul & Varricchio, David & Trexler, David. (October 2018). New Insights on a Unique Eggshell Locality within the Late Cretaceous Upper Two Medicine Formation of Montana.
